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| author | Simon Peyton Jones <simon.peytonjones@gmail.com> | 2023-03-02 11:26:17 +0000 |
|---|---|---|
| committer | Simon Peyton Jones <simon.peytonjones@gmail.com> | 2023-03-03 08:13:44 +0000 |
| commit | 53c4b80add408db9f305b61a5fe3abe23b0a55e1 (patch) | |
| tree | 5cdfaf6b8289500a3968a086d6f95df3c3cb4156 /compiler/GHC/Core/DataCon.hs | |
| parent | 2f97c86151d7eed115ddcbdee1842684aed63176 (diff) | |
| download | haskell-wip/T22023.tar.gz | |
More fixes for `type data` declarationswip/T22023
This MR fixes #23022 and #23023. Specifically
* Beef up Note [Type data declarations] in GHC.Rename.Module,
to make invariant (I1) explicit, and to name the several
wrinkles.
And add references to these specific wrinkles.
* Add a Lint check for invariant (I1) above.
See GHC.Core.Lint.checkTypeDataConOcc
* Disable the `caseRules` for dataToTag# for `type data` values.
See Wrinkle (W2c) in the Note above. Fixes #23023.
* Refine the assertion in dataConRepArgTys, so that it does not
complain about the absence of a wrapper for a `type data` constructor
Fixes #23022.
Acked-by: Simon Peyton Jones <simon.peytonjones@gmail.com>
Diffstat (limited to 'compiler/GHC/Core/DataCon.hs')
| -rw-r--r-- | compiler/GHC/Core/DataCon.hs | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/compiler/GHC/Core/DataCon.hs b/compiler/GHC/Core/DataCon.hs index a9e540769e..f54f42d99d 100644 --- a/compiler/GHC/Core/DataCon.hs +++ b/compiler/GHC/Core/DataCon.hs @@ -1669,13 +1669,25 @@ dataConOtherTheta dc = dcOtherTheta dc -- evidence, after any flattening has been done and without substituting for -- any type variables dataConRepArgTys :: DataCon -> [Scaled Type] -dataConRepArgTys (MkData { dcRep = rep - , dcEqSpec = eq_spec +dataConRepArgTys (MkData { dcRep = rep + , dcEqSpec = eq_spec , dcOtherTheta = theta - , dcOrigArgTys = orig_arg_tys }) + , dcOrigArgTys = orig_arg_tys + , dcRepTyCon = tc }) = case rep of - NoDataConRep -> assert (null eq_spec) $ map unrestricted theta ++ orig_arg_tys DCR { dcr_arg_tys = arg_tys } -> arg_tys + NoDataConRep + | isTypeDataTyCon tc -> assert (null theta) $ + orig_arg_tys + -- `type data` declarations can be GADTs (and hence have an eq_spec) + -- but no wrapper. They cannot have a theta. + -- See Note [Type data declarations] in GHC.Rename.Module + -- You might wonder why we ever call dataConRepArgTys for `type data`; + -- I think it's because of the call in mkDataCon, which in turn feeds + -- into dcRepArity, which in turn is used in mkDataConWorkId. + -- c.f. #23022 + | otherwise -> assert (null eq_spec) $ + map unrestricted theta ++ orig_arg_tys -- | The string @package:module.name@ identifying a constructor, which is attached -- to its info table and used by the GHCi debugger and the heap profiler |